Flahs, an evil old thing everyone seem to want to avoid. But the fact is, it usually works better than other alternatives.
Seeing many html5+js+css > Flash posts, and it's so nice when everyone is pointing out how awesome it is, until you try to do something useful like dubjoy. Where it turned out for you guys that flash is the only logical way to do it. I hope alternatives will get better soon, until then, we're stuck.